No and yes - it does not make one a cannibal (as other answers mentioned) but I think it does make one a monster.
Technically cannibalism is, as other answers mentioned, about eating one's own species - other species, even sapient ones, likely doesn't fit the definition. But the taboo behind that is a little broader, I think, it has to do with not eating beings one perceives as people.
One possible nod to this is the related taboo behind eating pets, or the species of animal routinely kept as pets - cats and dogs, for example, are rarely considered food (at least in the west) and cultures which would, are, well, kind of thought less of for that choice - and I'm not saying there's something intrinsic to those species for a reason why, just that people empathize with pets, and so don't think of them as food.
Another possible related concept is that there were plenty of times, historically, that people of different races were considered "not quite human" - subhuman, or animalistic, or just generally not-people. I recall reading about laws that did not consider the killing of native individuals "murder" because they "weren't people" - not to mention various inequalities of legal protection in regards to rape, abuse, exploitation, and so on related to these racist ideas. But while a great many abuses were common while these legal ideas lasted, I do not recall hearing that cannibalism was one of them. This seems relevant because people at that time certainly believed, acted like they believed, the difference between different ethnicities or cultures was as great as the differences between species - perhaps as great as the differences actually are between these hominid races you mention - yet the cannibalism taboo held.
So I think that the underlying taboo is a bit broader than its literal definition, and it would certainly cover even completely separate races that are known to be sapient. Probably a person in that situation would consider eating other species "cannibalistic" even if the term didn't quite apply logically, it would feel similar, I think. And they, or others, would feel that a person who did eat the flesh of other races is a bad person, monstrous, nasty, badwrongevil.
To quote a webcomic "food that talks is not food", and I think people of your world would feel that way even if there are social, or even legal, definitions that hold that some races or species are "not-people" and can be abused or murdered without consequence - they would not likely be eaten, except under circumstances (and with such consequences) that a person might consider cannibalism - like extreme survival or certain kinds of cultural elements.
To get back to your question, it may be that there's a separate term for those who eat other (sapient) species as opposed to their own, or it might be the same term (cannibal) would be more broadly applied in such a world to begin with. But probably the average person in such a situation would not consider eating the flesh of other sapient species unless they would consider eating the flesh of their own species under those circumstances, and generally, people would probably react about the same to someone who did... so any difference in term is probably not hugely relevant.